1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Induced current question

  1. Oct 31, 2005 #1
    I'm working on a question that I could use some help on. The problem basically says there is a solenoid with a current running through it given by an equation. There is a wire that is coaxial with and surrounding the solenoid, and the wire makes two loops around the solenoid. A resistance for the wire is also given. The question wants to know what the current in the wire is. Now, I know that if the wire was only looping around the solenoid once, I could just use faraday's law to calculate the induced emf, and then use I=[tex]\xi[/tex]/R. What I can't figure out is how does the fact that there are two loops in the wire affect the induced current? Thanks for any replies.
  2. jcsd
  3. Oct 31, 2005 #2


    User Avatar
    Gold Member

    The equation for induced current if the wire is wrapped n times around the magnetic field is:
    [tex] I = \frac{\xi}{R} = \frac{n \dot{\phi_{t}}}{R} [/tex]
    Last edited: Oct 31, 2005
  4. Oct 31, 2005 #3
    Thanks for the quick reply. I'm just a tad confused about your notation. Are you saying that in this case I = 2[tex]\xi[/tex]/R? Or that if the emf is known, then it is always simply I=[tex]\xi[/tex]/R?

    Edit: Oh, ok. I didn't see your edit there. Thanks for the help.
    Last edited: Oct 31, 2005
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook